Pressure-relief valve for reducing pressure arising in a cell-like cavity, such as a battery cell

Abstract

A pressure relief valve for reducing pressure arising in a cell-like cavity, such as a battery cell, including a cover which has a seal for sealing a housing opening up to a predetermined cell pressure and is provided with a holding device in order to hold said cover on the housing opening, the holding device having a spring clip which is attached to the lower face of the cover that faces the housing opening and has a plurality of radially outwardly directed spring tongues which, at the ends thereof, are provided with spring portions which, when the cover is pressed onto the housing opening, can be moved back resiliently in the radial direction through the opening edge and, after passing through the housing opening, snap back under a wall region around the opening edge, wherein a bearing device, which is separate from the cover prior to mounting and to which the spring clip is fixed by a support part, is connected to the cover on the lower face thereof that faces the housing opening, a connection adapter being connected to the center of the bearing device, wherein a central opening of the spring is placed on the connection adapter and wherein the support part is connected to the connection adapter, thus fixing the spring clip.

The invention claimed is: 
     
       1. A pressure relief valve for reducing pressure arising in a cavity of a cell, comprising:
 a cover ( 2 ) which has a seal ( 21 ) for sealing a housing opening ( 11 ) up to a predetermined cell pressure and has a holding device to hold said cover on the housing opening ( 11 ), 
 wherein the holding device has a spring clip ( 22 ) attached to the lower face of the cover ( 2 ) that faces the housing opening ( 11 ) and has a plurality of radially outwardly directed spring tongues ( 220 ) which at the ends thereof have spring portions ( 221 ,  222 ) which, when the cover ( 2 ) is pressed onto the housing opening ( 11 ), can be moved back resiliently in the radial direction through the opening edge, and, after passing through the housing opening, snap back under a wall region around the opening edge, 
 a bearing device ( 201 ), which is separate from the cover prior to mounting and to which the spring clip ( 22 ) is fixed by a support part ( 23 ), the bearing device ( 201 ) being connected to the cover ( 2 ) on the lower face thereof that faces the housing opening ( 11 ), and 
 a connection adapter ( 203 ) connected to the center of the bearing device ( 201 ), wherein a central opening of the spring clip ( 22 ) is placed on the connection adapter ( 203 ) and the support part ( 23 ) is connected to the connection adapter ( 203 ), thus fixing the spring clip ( 22 ), and 
 wherein the cover ( 2 ) is equipped as a cover unit having two cover parts ( 20 ,  25 ) which are separated prior to the assembly of said cover, which unit has a first cover part ( 20 ) on the lower face facing the housing opening ( 11 ) and a second cover part ( 25 ), which is connected to the first cover part ( 20 ), on the upper face facing away from the housing opening ( 11 ). 
 
     
     
       2. The pressure relief valve according to  claim 1 , wherein the connection adapter ( 203 ) is designed such that the bearing device ( 201 ), the spring clip ( 22 ) and the support part ( 23 ) are oriented relative to one another in a fixed rotational position by said connection adapter. 
     
     
       3. The pressure relief valve according to  claim 2 , wherein the bearing device ( 201 ) and the spring clip ( 22 ) have a star shape in an axial plan view of the pressure relief valve, having a number of 2n arms and 2n spring tongues ( 220 ), the connection adapter ( 203 ) has a non-round shape in the axial plan view and the support part ( 23 ) has a star shape having a number of n arms, where n is a positive integer. 
     
     
       4. The pressure relief valve according to  claim 3 , wherein the connection adapter ( 203 ) has a shape which is angular in the axial plan view, having a number of n corners. 
     
     
       5. The pressure relief valve according to  claim 4 , wherein the bearing device ( 201 ) and the connection adapter ( 203 ) are formed in one piece with one another or integrally bonded or latched or screwed together, and the connection adapter ( 203 ) and the support part ( 23 ) are latched or screwed together. 
     
     
       6. The pressure relief valve according to  claim 5 , wherein the spring portions ( 221 ,  222 ), in the longitudinal portion thereof extending in the radial direction, are recessed downward away from the cover ( 2 ) in a U-shape and in the mounted state of the pressure relief valve, the free edges of the radially outer U-legs of the spring portions ( 221 ,  222 ) each form a support surface engaging under the wall region around the housing opening ( 11 ). 
     
     
       7. The pressure relief valve according to  claim 6 , wherein at least some of the spring portions ( 221 ) are spaced apart from the lower face of the cover ( 2 ) to such an extent that, in the mounted state, the seal ( 21 ) is held under pressure on the upper face of the wall region around the opening edge. 
     
     
       8. The pressure relief valve according to  claim 7 , wherein a further proportion of the spring portions ( 222 ) is spaced apart from the lower face of the cover part ( 2 ) to such an extent that, in the mounted state, said spring portions are spaced apart from the lower face of the wall region around the opening edge. 
     
     
       9. The pressure relief valve according to  claim 8 , wherein the spring tongues ( 220 ) which are connected to the spring portions ( 222 ) which are spaced further apart from the lower face of the cover ( 2 ) are supported and/or stiffened from below by the support part ( 23 ). 
     
     
       10. The pressure relief valve according to  claim 9 , wherein the spring clip ( 22 ) is supported and positioned on bearing structures ( 202 ) on the lower face of the bearing device ( 201 ), projections engaging in the depressions in the U-shaped spring portions ( 221 ,  222 ) and the bearing structures being designed such that the radially outer spring portions ( 221 ,  222 ) can be pivoted inward. 
     
     
       11. The pressure relief valve according to  claim 1 , wherein the bearing device ( 201 ) and the spring clip ( 22 ) have a star shape in an axial plan view of the pressure relief valve, having a number of 2n arms and 2n spring tongues ( 220 ), the connection adapter ( 203 ) has a non-round shape in the axial plan view and the support part ( 23 ) has a star shape having a number of n arms, where n is a positive integer. 
     
     
       12. The pressure relief valve according to  claim 1 , wherein the connection adapter ( 203 ) has a shape which is angular in an axial plan view, having a number of n corners. 
     
     
       13. The pressure relief valve according to  claim 1 , wherein the bearing device ( 201 ) and the connection adapter ( 203 ) are formed in one piece with one another or integrally bonded or latched or screwed together, and the connection adapter ( 203 ) and the support part ( 23 ) are latched or screwed together. 
     
     
       14. The pressure relief valve according to  claim 1 , wherein the spring portions ( 221 ,  222 ), in the longitudinal portion thereof extending in the radial direction, are recessed downward away from the cover ( 2 ) in a U-shape and in the mounted state of the pressure relief valve, the free edges of the radially outer U-legs of the spring portions ( 221 ,  222 ) each form a support surface engaging under the wall region around the housing opening ( 11 ). 
     
     
       15. The pressure relief valve according to  claim 1 , wherein at least some of the spring portions ( 221 ) are spaced apart from the lower face of the cover ( 2 ) to such an extent that, in the mounted state, the seal ( 21 ) is held under pressure on the upper face of the wall region around the opening edge. 
     
     
       16. The pressure relief valve according to  claim 1 , wherein a further proportion of the spring portions ( 222 ) is spaced apart from the lower face of the cover part ( 2 ) to such an extent that, in the mounted state, said spring portions are spaced apart from the lower face of the wall region around the opening edge. 
     
     
       17. The pressure relief valve according to  claim 1 , wherein the spring tongues ( 220 ) which are connected to the spring portions ( 222 ) which are spaced further apart from the lower face of the cover ( 2 ) are supported and/or stiffened from below by the support part ( 23 ). 
     
     
       18. The pressure relief valve according to  claim 1 , wherein the spring clip ( 22 ) is supported and positioned on bearing structures ( 202 ) on the lower face of the bearing device ( 201 ), projections engaging in the depressions in the U-shaped spring portions ( 221 ,  222 ) and the bearing structures being designed such that the radially outer spring portions ( 221 ,  222 ) can be pivoted inward. 
     
     
       19. Assembly kit for constructing a pressure relief valve according to  claim 1 , wherein at least two bearing devices ( 201 ) of different heights having connection adapters ( 203 ), at least one spring clip ( 22 ), at least one support part ( 23 ) and at least one assembled cover ( 2 ), are present. 
     
     
       20. A container comprising at least one cell cavity, in particular a battery or a rechargeable battery, having at least one pressure relief valve according to  claim 1 . 
     
     
       21. A pressure relief valve for reducing pressure arising in a cavity of a cell, comprising:
 a cover ( 2 ) which has a seal ( 21 ) for sealing a housing opening ( 11 ) up to a predetermined cell pressure and has a holding device to hold said cover on the housing opening ( 11 ), 
 the holding device having a spring clip ( 22 ) attached to the lower face of the cover ( 2 ) that faces the housing opening ( 11 ) and has a plurality of radially outwardly directed spring tongues ( 220 ) which, at the ends thereof have spring portions ( 221 ,  222 ) which, when the cover ( 2 ) is pressed onto the housing opening ( 11 ), can be moved back resiliently in the radial direction through the opening edge, 
 wherein after passing through the housing opening snap back under a wall region around the opening edge, a bearing device ( 201 ), which is separate from the cover prior to mounting and to which the spring clip ( 22 ) is fixed by a support part ( 23 ), is connected to the cover ( 2 ) on the lower face thereof that faces the housing opening ( 11 ), 
 wherein a connection adapter ( 203 ) is connected to the center of the bearing device ( 201 ), a central opening of the spring clip ( 22 ) is placed on the connection adapter ( 203 ), the support part ( 23 ) is connected to the connection adapter ( 203 ), thus fixing the spring clip ( 22 ), and 
 wherein the cover ( 2 ) is equipped as a cover unit having two cover parts ( 20 ,  25 ) which are separated prior to the assembly of said cover, which unit has a first cover part ( 20 ) on the lower face facing the housing opening ( 11 ) and a second cover part ( 25 ), which is connected to the first cover part ( 20 ), on the upper face facing away from the housing opening ( 11 ), 
 wherein the connection adapter ( 203 ) is designed such that the bearing device ( 201 ), the spring clip ( 22 ) and the support part ( 23 ) are oriented relative to one another in a fixed rotational position by said connection adapter, 
 wherein the bearing device ( 201 ) and the spring clip ( 22 ) have a star shape in an axial plan view of the pressure relief valve, having a number of 2n arms and 2n spring tongues ( 220 ), the connection adapter ( 203 ) has a non-round shape in the axial plan view and the support part ( 23 ) has a star shape having a number of n arms, where n is a positive integer, 
 wherein the connection adapter ( 203 ) has a shape which is angular in the axial plan view, having a number of n corners 
 wherein the bearing device ( 201 ) and the connection adapter ( 203 ) are formed in one piece with one another or integrally bonded or latched or screwed together, and the connection adapter ( 203 ) and the support part ( 23 ) are latched or screwed together, 
 wherein the spring portions ( 221 ,  222 ), in the longitudinal portion thereof extending in the radial direction, are recessed downward away from the cover ( 2 ) in a U-shape and in the mounted state of the pressure relief valve, the free edges of the radially outer U-legs of the spring portions ( 221 ,  222 ) each form a support surface engaging under the wall region around the housing opening ( 11 ), 
 wherein at least some of the spring portions ( 221 ) are spaced apart from the lower face of the cover ( 2 ) to such an extent that, in the mounted state, the seal ( 21 ) is held under pressure on the upper face of the wall region around the opening edge, 
 wherein a further proportion of the spring portions ( 222 ) is spaced apart from the lower face of the cover part ( 2 ) to such an extent that, in the mounted state, said spring portions are spaced apart from the lower face of the wall region around the opening edge, 
 wherein the spring tongues ( 220 ) which are connected to the spring portions ( 222 ) which are spaced further apart from the lower face of the cover ( 2 ) are supported and/or stiffened from below by the support part ( 23 ), 
 wherein the spring clip ( 22 ) is supported and positioned on bearing structures ( 202 ) on the lower face of the bearing device ( 201 ), projections engaging in the depressions in the U-shaped spring portions ( 221 ,  222 ) and the bearing structures being designed such that the radially outer spring portions ( 221 ,  222 ) can be pivoted inward, and 
 wherein the cover ( 2 ) is equipped as a cover unit having two cover parts ( 20 ,  25 ) which are separated prior to the assembly of said cover, which unit has a first cover part ( 20 ) on the lower face facing the housing opening ( 11 ) and a second cover part ( 25 ), which is connected to the first cover part ( 20 ), on the upper face facing away from the housing opening ( 11 ). 
 
     
     
       22. The pressure relief valve according to  claim 21 , wherein a gas-permeable, at least largely moisture-impermeable membrane ( 24 ) is arranged between the two cover parts ( 20 ,  25 ). 
     
     
       23. The pressure relief valve according to  claim 22 , wherein the bearing device ( 201 ) and/or the second cover part ( 25 ) is releasably latched or screwed or non-releasably connected, in particular welded or glued, to the first cover part ( 20 ). 
     
     
       24. The pressure relief valve according to  claim 22 , wherein the membrane ( 24 ) is glued or welded to the first cover part ( 20 ) or the membrane ( 24 ) is held by the cover parts ( 20 ,  25 ). 
     
     
       25. The pressure relief valve according to  claim 24 , wherein the membrane ( 24 ) is connected to the first cover part ( 20 ) in a fluid-tight manner in a radial outer region. 
     
     
       26. The pressure relief valve according to  claim 25 , wherein at least one flow path for the passage of gas is formed by at least one channel portion ( 26 ) arranged between the cover parts ( 20 ,  25 ), and is connected to at least one opening to the cavity on one side and to the outside space around the cover ( 2 ) on the other side. 
     
     
       27. The pressure relief valve according to  claim 26 , wherein a plurality of channel portions ( 26 ) is present and the channel portions ( 26 ) are delimited on the upper face of the first cover part ( 20 ) that faces away from the housing opening ( 11 ) and/or on the lower face of the second cover part ( 25 ) that faces the housing opening ( 11 ) by depressions in the cover parts ( 20 ,  25 ) or by spacers ( 28 ) which are arranged thereon and formed in one piece therewith and spacers ( 27 ) which are arranged on the radial outer face of the first cover part ( 20 ) and/or the second cover part ( 25 ) and are formed in one piece therewith. 
     
     
       28. The pressure relief valve according to  claim 21 , wherein the bearing device ( 201 ) and/or the second cover part ( 25 ) is releasably latched or screwed or non-releasably connected, welded or glued, to the first cover part ( 20 ). 
     
     
       29. The pressure relief valve according to  claim 22 , wherein the membrane ( 24 ) is connected to the first cover part ( 20 ) in a fluid-tight manner in a radial outer region. 
     
     
       30. The pressure relief valve according to  claim 21 , wherein at least one flow path for the passage of gas is formed by at least one channel portion ( 26 ) arranged between the cover parts ( 20 ,  25 ), and is connected to at least one opening to the cavity on one side and to the outside space around the cover ( 2 ) on the other side.